The most important step in purifying water is a complete disinfection of the water prior to filtering. Often, complete disinfection is not accomplished because either the process is interrupted prior to completion or insufficient disinfecting agent is introduced to the water. The present invention overcomes these problems by providing an automatically controlled disinfecting period prior to filtering, while also including a disinfecting agent introduced in a primary container. The duration of the disinfecting period is controlled by a physicochemical time control switch contained within a compact, disposable, multi-stage filter cartridge positioned between a primary water container for untreated water and a secondary container, which receives purified water. Prior art devices either do not provide a disinfecting step, do not include a timed disinfecting step, and/or do not include a primary treatment water container pre-charged with disinfecting agent. With the present invention, after the disinfecting step is complete, a physicochemical time switch located within a filter cartridge allows the flow of disinfected water from the primary water container into the filtering elements of the filter cartridge after an appropriate amount of time has lapsed for effective disinfecting. The present system assures that the water will be properly disinfected for an appropriate time period prior to filtering and purifying.
Prior art devices include: Iana et al, U.S. Pat. No. 5,122,272 which describes a water purifier container with a filter element extending into the neck of the container with a sipping tube extending from a lower chamber of the filter while water within the container enters the filter into an upper chamber. The Iana patent also describes numerous prior art devices, the U.S. Pat Nos. being: 4,852,781; 4,741,550; 4,443,336; 4,298,475; 4,090,650; 3,731,717; 3,389,803; and 2,738,105.